Network Analysis of Counter-strike and Starcraft

Mark Claypool, David LaPoint, Josh Winslow

Worcester Polytechnic InstituteWorcester, MA, USA

http://www.cs.wpi.edu/~claypool/

Why Study Games?

• Rapidly growing in popularity [9]– 18 million on-line gamers, 1.6 billion dollar industry– Growing fraction of network traffic– Game consoles (Xbox, PS2, GameCube) online

• Previous studies measured Web or Multimedia traffic– Games are different low latency, small packets,

bursty traffic

• Possible benefits– Design networks to better accommodate network

game traffic “turbulence”– Provide data for more realistic network simulations

Network analysis of Counter-strike and Starcraft

What is Counter-strike?

What is Counter-strike?

Why Study Counter-strike? (1 of 2)

Neverwinter Nights

America's Army: Operations

Soldier of Fortune 2: Double Helix

Unreal Tournament 2003

Return to Castle Wolfenstein

Unreal Tournament

Battlefield 1942

Quake III Arena

MedalOfHonor: Allied Assault

Half-Life

0 20000 40000 60000 80000 100000

Serverspy FPS rankings (10/31/2002)

# of players

• Gaming traffic dominated by first-person shooter (FPS) genre [9]

(Feng et al, IMW 2002)

Why Study Counter-strike? (2 of 2)

Action Half-Life

Front Line Force

Vampire Slayer

SvenCo-op

Firearms

The Specialists

Deathmatch

Team Fortress Classic

Day of Defeat

Counter-Strike

0 10000 20000 30000 40000 50000 60000 70000 80000

Serverspy HL mod rankings (10/31/2002)

# of players

What is Starcraft?

Why Study Starcraft?

•Real-Time Strategy (RTS) popular genre alternative to FPS

•Starcraft – Best-selling game in 1998– Dozens of awards– Entrenched user base, especially in Korea– About 15% of Battle.net games are

Starcraft

Outline

•Introduction (done)

•Experimental Setup next

•Analysis– Game Architectures– Bandwidth Use– Packet Sizes and Arrival

•Conclusions

Experimental Setup

• Game client (and server)– PIII 800 MHz– nVidea geForce 2 3d w/64 Mbytes memory– 512 Mbytes RAM – 10 Mbps NIC

• Sniffer PC ran Commview

• Runs: Starcraft 2-8 players, Counter-strike 3-10 players

Internet

Game Client

Hub

Game Server

Sniffer

Campu

s

Game Architectures

•Counter-strike (CS)– Client-server– Clients send data only to server– Server maintains game state– Server sends all user actions to every

other user

•Starcraft (SC)– Peer-to-peer– Clients periodically send user actions to

every other user

SC Bandwidth Sent and Game Size

Averages: 650 bytes/sStddev: 30%

+1500/12% per pairEven bandwidth per user

CS Bandwidth Sent by ClientAverage: 2690 bytes/s

Stddev: 110%Bandwidth differs per client

(Map change)

CS Bandwidth Sent by ServerAverage: 6470 bytes/s

Stddev: 135%

(Map change)

Bandwidth Analysis Summary

•Starcraft more consistent than Counter-strike– Starcraft clients sends similar – Counter-strike clients sends vary

•Largest games still possible over a modem– Starcraft can have up to 8– Counter-strike can have up to 32– Counter-strike server may have network

bottleneck

Packet Sizes

CS Packet Sizes by Server

Packet Interarrival Times

Packet Analysis Summary

•Counter-strike and Starcraft have significantly smaller packets than typical (400 bytes [9])

•Counter-strike sends bursts of small packets, while Starcraft steadier

•Number of players does not affect packet sizes for Starcraft or Counter-strike clients

•Server packet sizes and rates very considerably depending upon the action and number of players

Conclusions

•Network games different than typical Internet applications– Very interactive– Small, bursts of UDP packets

•Starcraft (RTS)– Steadier data rate scales linearly with users– Small packet sizes

•Counter-strike (FPS)– Burstier data rate depending upon action– Packet sizes for server depend upon action

Future Work

•Incorporate into simulator for network impact studies (NS-2)– Simulate “rounds” in Counter-strike

•Other RTS and FPS games– Warcraft III (RTS)– America’s Army (FPS)

•Other genres and games– The Sims Online

•Data traces available at:http://perform.wpi.edu/downloads/

Network Analysis of Counter-strike and Starcraft

Mark Claypool, David LaPoint, Josh Winslow

Worcester Polytechnic InstituteWorcester, MA, USA

http://www.cs.wpi.edu/~claypool/